3 ms·

Sapphire is aluminum oxide. The transparent aluminum you're talking about was invented in 2009.

• ajtaylor 14y ago
  I know it's not exactly the same, but I couldn't resist the temptation.
  • acchow 14y ago
    Not exactly the same? It's not at all the same. It's like calling oxygen (O2) "not exactly the same" as water (H2O), but you couldn't resist because they're both mostly transparent.
  • reeses 14y ago
    Never fear, alumin(i)um oxide is harder than elemental aluminum and is actually what you interact with outside a vacuum.
  • ajtaylor 14y ago
    Work with me here guys... You're spoiling the joke.